US6255552B1 - Composite dressing with separable components - Google Patents

Abstract

The dressing system of the present invention provides, in one aspect, a composite dressing that allows a wound to be dressed in one easy step and redressed without disturbing the wound. The composite dressing comprises a contact component having a bottom side facing a wound, and a top side. A dressing component is releasably attached to the top side of the contact component such that the dressing component can be readily separated from the contact component if pulled relative to the contact component. The contact component can remain on the wound to prevent disturbance, and another composite dressing or dressing component can be applied to the contact component.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. patent application Ser. No. 08/324,818, filed Oct. 17, 1994 now U.S. Pat. No. 5,994,613, the entire disclosure of which is incorporated herein by reference, which is a continuation of U.S. patent application Ser. No. 08/088,625, filed Jul. 1, 1993, now U.S. Pat. No. 5,910,125, which is a continuation of U.S. patent application Ser. No. 07/780,619, filed Oct. 23, 1991, entitled “Wound Dressing System,” abandoned.

TECHNICAL FIELD

This invention relates to a wound dressing system for treating wounds. In one aspect, it relates to such a wound dressing system that prevents disturbance of wounds caused by dressing changes.

BACKGROUND OF THE INVENTION

The treatment of wounds with dressings involves a wide variety of situations and applications. A corresponding variety of different types of dressings are available for treating wounds. Dressings have been designed to contain various medicaments and solutions for either absorption into the wound or to wick or remove fluids from the wound area to maintain a proper moisture level at the wound. These dressings typically have some type of absorbent as part of the dressing. Occlusive dressings have been designed to include properties that protect a wound from outside elements, while yet maintain a proper moisture level at the wound and trap the tissue's natural healing fluids. Pressure dressings have been designed to keep pressure on a wound. Body tissues encounter a wide variety of wounds, for example, abrasions, lesions, skin grafts, burns, and pressure sores. Each type of wound undergoes several stages of healing and may require different modes of treatment depending on the stage of healing. Thus, the treatment of a wound involves the selection of a dressing based on the particular type of wound and the various healing stages that are contemplated. Considerations such as size, location and extent of infection of the wound also play a role in selecting a dressing.

However, regardless of the various considerations, the treatment of wounds necessarily involves the periodic changing of the dressings being used to treat the wound. Dressings must be repeatedly removed and replaced for various reasons, for example, to irrigate and cleanse the wound, to reapply medicament, to replace a saturated or soiled dressing, to prevent incorporation of the dressing into the wound, or to merely inspect the wound.

The problem attendant with changing dressings is that the wound is often disturbed during the removal of the dressings. This disturbance of the wound is usually caused when the dressing has wholly or partially adhered to the wound, whereby removal of the dressing destroys any healing that has already occurred, for example, the formation of granulation tissue or the buildup of fibrin which helps clot the blood. Also, and equally as important, removal of an adhered dressing causes great pain to the patient, especially when the wound is at a healing stage where new nerve endings are forming in the wound. The high potential for such wound damage and pain requires extensive nursing time to remove and replace dressings with various techniques to help reduce the wound damage and pain.

The term “adherence” has not been clearly defined in the field of tissue dressings. “Adherence” of a dressing to a wound is typically narrowly defined as when exudate from a wound has dried to and bound with some part of a dressing such as an absorbent. With this narrow definition of adherence in mind, “non-adherent” materials are claimed to have been developed which can be interposed between a wound and a dressing.

Such interposing of “non-adherent” materials has been carried out by two methods. The first method involves a first step of placing a layer of “non-adherent” material over the wound and a second step of placing a separate dressing over the “non-adherent” material. U.S. Pat. No. 4,638,796 to Sims discloses such a method. However, this method involves two application steps and two separate materials to be applied on a wound. The need for sterile dressings and application procedures makes such a two step method appreciably more cumbersome than applying a single dressing. There is also a substantial risk that because of a busy hospital, untrained care providers, or some other mistake or circumstance, the dressing will be applied without first applying the layer of “non-adherent” material. Such an omission could very likely result in the dressing “adhering” to the wound. Another problem with this method is that because of the nature of the “non-adherent” materials, they can be difficult to keep in place while applying the separate dressing. Sometimes the non-adherent materials must be secured in place over the wound before the separate dressing can be applied.

An additional drawback of placing a layer of non-adherent material on the wound and then a dressing over the wound is that, with some types of wounds and some types of dressings, a single layer of non-adherent material will not sufficiently prevent bonding between the wound and the dressing. Applying more than one layer of non-adherent material becomes a cumbersome process in the typical wound care situation. For example, hydrocolloid dressings, such as DuoDERM® made by Convatec®, have a tendency to become very sticky and viscous when in contact with wound exudate. A single layer non-adherent material often does not adequately prevent the hydrocolloid material from working or permeating through the interstices of the non-adherent material and bonding to the wound. If the mesh of the non-adherent material is too tight, liquid may pool at the wound, and be unable to properly pass through the non-adherent material. This creates a potential for maceration of the wound.

The second method of interposing a “non-adherent” material between a wound and dressing involves the use of an integral dressing that has one or more layers of “non-adherent” material laminated or joined to it. This type of dressing is supposed to prevent the wound from “adhering” to the dressing in the narrow sense of the term “adherence”, however, redressing a wound with these dressings involves removing the entire dressing, including the “non-adherent” material. U.S. Pat. No. 4,667,665 to Blanco et al. discloses one such dressing: an integral closed dressing with an outer casing that encloses layers of an absorbent and is sealed at its peripheral edges. One side of the dressing casing is two layers of “non-adherent” material. It has been found that removal of these types of dressings without causing pain involves soaking the dressings with a saline solution and then teasing the dressings off of the wound. This process involves intensive nursing time to set up a sterile basin with solution, soak the dressings and then painstakingly tease off the dressings. The soaked dressing presents a disposal problem in that the dressing is dripping wet and often tears apart.

The process of removing these internal dressings can appreciably disturb wounds so as to cause pain and delay healing of the patient. Further, removal of these dressings often requires a qualified care provider to “tease” the dressing off of the wound to minimize disturbance of the wound. As noted above, such teasing and manipulation of these dressings entails additional nursing time as well as additional pain and anxiety that the patient must endure during a dressing change. Sometimes these dressings are torn apart in an effort to prevent removal of a part of the dressing that has adhered to a wound. Such tearing at the wound site is cumbersome, time consuming and often creates a mess as the different layers of the dressings, especially the absorbent, tear apart.

User instructions for the commercial embodiment of the invention disclosed in the Blanco et al. patent disclose an alternate method of removal which requires soaking the dressing, then cutting along its outer edges while the dressing is wet with saline and then peeling away the top layers to leave a layer of “non-adherent” on the wound. Cutting the dressing requires the delicate use of a cutting instrument at the surface of the patient's skin. Again, such a cumbersome task requires intensive nursing time to delicately cut around the dressing edge without accidentally contacting the patient's skin or sensitive wound with the cutting instrument.

A drawback of the so-called “non-adherent” materials is that, although they are “non-adherent” relative to the dressings with which they are used, they are not completely non-adherent. The various types of “non-adherent” material have interstices in which the exudate can dry. Also, in certain situations such as a pressure dressing or a packing dressing, the dressing is pressed onto the treatment area causing the “non-adherent” material to be pressed into the wound so that granulation tissue and epithelial cells are forced into the interstices of the “non-adherent” material. Thus, calling these materials “non-adherent” is a partial misnomer because they can still stick, cling, or otherwise adhere to a wound so as to disturb the wound when such materials are removed.

Thus, a need exists for a dressing system that, regardless of the wound treatment situation, prevents disturbance of wounds caused by dressing changes. Also, a need exists for a dressing system that eliminates the risk that a dressing will be applied, that cannot thereafter be removed without disturbing the wound. Due to the potential for wound disturbance and patient pain caused by dressing changes, care providers are hesitant to remove dressings. A further need exists for a dressing system that eliminates such a potential so that care providers can be free to inspect a wound as often as needed, and dressings can be left on a wound as long as desired or changed as frequently as desired.

Also standardization of the treatment of wounds and simplification of such treatment is much needed. Care providers range from doctors to nurses to inexperienced patients treating themselves. Also, it is very common that the care provider who removes a dressing is not the same care provider who dresses the wound, and thus the care provider removing the dressing will often know nothing about the type of wound or the present healing stage of the wound. Thus, a need exists for a dressing system that provides a dressing that will not harm a wound regardless of the stage of healing of the wound at the time of a dressing change. Further, a need exists for a dressing system that allows such a dressing to be applied in one simple and efficient step, as opposed to a two step treatment.

Care providers often initially treat wounds without knowing if a different dressing or method will ultimately be required and thus a standardized initial treatment of wounds is needed such that once a wound is inspected by a qualified care provider and a decision is made as to the desired treatment, a dressing change can be made easily without fear of disturbing the wound. Thus, a need exists for a dressing system that can be universally used as the initial form of treatment of a wound.

Another aspect of wound treatment is irrigation and cleansing of wounds between dressing changes. Various syringes and bulbs are used by different care providers to irrigate and cleanse wounds. Forces associated with such irrigation and cleansing can harm developing epithelial tissue or otherwise disturb a wound. A need exists for a shield to protect the wound from forces associated with irrigation and cleansing of the wound, and especially a shield that is transparent to readily allow inspection of the wound.

Also, a need exists for a product that has more than one layer of non-adherent material, that can be applied over a wound in one step before a dressing, and that prevents adherence of the dressing to the wound as well as help maintain the proper moisture level at the wound.

One object of the present invention is to provide a dressing system that allows a dressing to be applied in one efficient step and allows redressing of the wound without disturbing the wound. Another object of the present invention is to provide a dressing system that has a built-in precautionary measure, or “safety”, that prevents a wound from being disturbed during a dressing change if part of the dressing adheres to the wound. Another object of the present invention is to provide a versatile dressing system that can be used on all types of wounds and wound treatment situations. Another object of the present invention is to provide a dressing system that leaves a “window” to the wound when the dressing is removed and thus allows the wound to be inspected, irrigated and cleansed while at the same time protecting the wound from irrigation forces.

SUMMARY OF THE INVENTION

The present invention provides a dressing system that allows a dressing to be applied in one step and easily changed without disturbing the wound. In accordance with one aspect, the dressing system provides a composite dressing that comprises a contact component having a bottom side for facing the wound, and a top side; and a dressing component disposed on the top side of the contact component and releasably attached to the contact component such that the dressing component can be readily separated from the contact component if purposefully pulled relative to the contact component. In one aspect of the present invention, after the composite dressing is applied to the wound, the dressing component will readily separate from the contact component when pulled, in the event the contact component adheres to the wound. In another aspect of the present invention, after the composite dressing is applied to the wound, the dressing component will readily separate from the contact component when pulled, if the contact component is held in place over the wound while the dressing component is pulled. In another aspect of the present invention, the top side of the contact component is readily accessible by one or more fingers to apply pressure on the contact component to hold it in place, while the dressing component is pulled and separated therefrom.

Another aspect of the dressing system of the present invention provides a method of treating wounds with composite dressings. A composite dressing with a dressing component releasably attached to a contact component is placed over a wound. When the dressing component requires removal or changing, it can be pulled from the wound and readily separated from the contact component. Importantly, in order to redress the wound, another composite dressing can be placed over the old contact component covering the wound, or a new dressing component can be separated from a new composite dressing and placed over the old contact component and the wound. In another aspect of the present invention, a predetermined additional dressing can be applied over the composite dressing.

Another aspect of the dressing system of the present invention is a contact component that provides a “window” to the wound so that the wound can be irrigated, cleansed or inspected with the contact component on the wound, while at the same time the contact component maintains the integrity of the wound during irrigation and cleansing.

The contact component of the composite dressing of the present invention may not require as frequent changing as the dressing component. Thus, to avoid unnecessary disturbance of a wound the dressing component can be readily separated from the contact component. In this way the contact component remains on the wound and protects it from the more frequent removals of the dressing component. Since the contact component may not need to be changed it can remain on the wound through several dressing changes.

If the contact component needs to be changed, it can be carefully removed after the dressing component is first removed. In this manner, the dressing component is not on top of the contact component to interfere with the removal of the contact component. Also, without the dressing component on top of the contact component, removal of the contact component can be facilitated by spraying or rinsing through the contact component so as to quickly “float” the contact component off the wound. If the dressing component remained attached to the contact component, such “floating” would require large volumes of sterile fluid to soak off the dressing. Even if the contact component must be changed as often as the dressing component, the present invention allows the dressing component to be readily removed first to facilitate easier removal of the contact component.

In the preferred embodiment of the present invention, the contact component is sufficiently transparent to allow inspection of the wound and sufficiently permeable to allow irrigation and cleansing of the wound, thus it is contemplated that there will be fewer occasions where the contact component needs to be changed. Also in the preferred embodiment, the contact component maintains the integrity of the wound during dressing changes and can protect the wound from forces associated with various irrigation methods.

Another aspect of the present invention is the provision of an interpositional wafer that comprises three layers of non-adherent material superimposed over each other and joined together. The middle layer has a tighter mesh than the two outer layers so that the wafer both properly controls the moisture level at the wound and prevents adherence between the wound and any dressing placed over the interpositional wafer. The wafer is applied to the wound in one quick step and then any suitable dressing can be placed over the wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and for further advantages thereof, reference is now made to the following detailed description of the invention taken in conjunction with accompanying drawings, in which:

FIG. 1 is a cross-sectional diagram of the preferred embodiment of the composite dressing of the present invention as applied on a wound.

FIG. 2 is a cross-sectional view of FIG. 1, taken alongline2—2 thereof, and further depicting the separation of the dressing component from the contact component.

FIG. 3 is a cross-sectional diagram of an alternative embodiment of the composite dressing of the present invention.

FIG. 4 is a cross-sectional diagram of an alternative embodiment of the composite dressing of the present invention.

FIG. 5 is a cross-sectional diagram of an alternative embodiment of the composite dressing of the present invention.

FIG. 6 is a cross-sectional diagram of an alternative embodiment of the composite dressing of the present invention with a predetermined additional dressing.

FIG. 7 is a top view of the composite dressing of the present invention.

FIG. 8 is an isometric view of an alternative embodiment of the composite dressing of the present invention.

FIG. 9 is a top view of an alternative embodiment of the composite dressing of the present invention.

FIG. 10 is a partial cross section of the embodiment of FIG. 9 taken alongline10—10 thereof.

FIG. 11 is a cross-sectional diagram of an alternative embodiment of the composite dressing of the present invention, before application to a wound.

FIG. 12 is a cross-sectional diagram of the embodiment of FIG. 11, as applies on a wound.

FIG. 13 is a cross-sectional diagram of the embodiment of FIG. 11, showing the dressing component being removed.

FIG. 14 is an isometric view of an alternative embodiment of the composite dressing of the present invention.

FIG. 15 is a cross-sectional diagram of an alternative embodiment of the composite dressing of the present invention.

FIG. 16 is a cross-sectional diagram of the embodiment of FIG. 15 depicting the separation of the dressing component from the contact component.

FIG. 17 is an illustration of an alternative embodiment of the composite dressing of the present invention in roll form.

FIG. 18 is an isometric view of a preferred embodiment of the interpositional wafer of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates the preferred embodiment of thecomposite dressing10 of the present invention in place over awound12. Composite dressing10 comprises adressing component20 releasably attached to acontact component14.Contact component14 has abottom side16 facing wound12 and has atop side18.Dressing component20 is disposed ontop side18 and is releasably attached to contactcomponent14 such thatdressing component20 can be readily separated fromcontact component14 if purposefully pulled relative to contactcomponent14.

Any material, combination of materials or arrangement of materials useful in treating wounds may be used as dressingcomponent20.Contact component14 must be sufficiently fluid permeable to allow dressing,component20 to be useful in treating the wound. Thus, any material, combination of materials or arrangement of materials suitable for contact with a wound and that allow thedressing component20 to be useful in treatingwound12 can be used. Also, materials can be interposed betweencontact component14 anddressing component20 that aid the releasable attachment of the dressingcomponent20 to thecontact component14 and/or are useful in treating the wound.

Dressing component20 can be releasably attached to contactcomponent14 in any manner as long as the dressing component can be readily separated from the contact component. The degree of attachment can vary. For example, the dressingcomponent20 can be very lightly attached to thecontact component14 so that it remains attached during application of thecomposite dressing10 to the wound, yet sufficiently weak that if thecontact component14 adheres even slightly to thewound12, the dressingcomponent20 will readily separate from thecontact component14 when pulled from the adhered contact component. Or, in another example, the dressingcomponent20 can be attached such that thecontact component14 needs to be held in place, for example with a finger or tape, while the dressingcomponent20 is pulled in order for the components to be readily separated. With either example thecontact component14 does not need to be moved once it is in place on the wound. It can stay in place by either pressing ontop side18 ofcontact component14 or by adherence ofcontact component14 to wound12.

For thedressing component20 to readily separate from thecontact component14, no cutting instrument is required nor does any component of thecomposite dressing10 need to be torn or ripped. In the preferred embodiment, the dressingcomponent20 remains intact while being readily separated from thecontact component14.

In the preferred embodiment, doublefaced tape42 is used to releasably attach thedressing component20 to thecontact component14. A one (1) mil polyester film coated on both sides with a pressure sensitive adhesive. It is presently preferred that one side be coated with an adhesive having 180° peel characteristic of about 40 oz./inch and the other side coated so as to have a lower 180° peel characteristic, for example, about 13 oz./inch. The weaker side is placed against thecontact component14 such that when the dressingcomponent20 is pulled relative to thecontact component14, the double faced tape will remain on thedressing component20. A similar degree of releasable attachment can be achieved by using a variety of adhesives, for example, cold seal adhesives, gum adhesives, acrylic adhesives, EVA adhesives, emulsion resins, water or solvent based adhesives, neoprenes, and thermoset powders and resins.

In FIG. 1, dressingcomponent20 additionally comprises facingsheet32, anabsorbent material30 and atop sheet34. As noted above, dressingcomponent20 is releasably attached to contactcomponent14 between facingsheet32 andtop side18. Facingsheet32 andtop sheet34 can also be any variety of suitable dressing materials, for example, non-woven polymers, netting materials, various plastic sheets perforated with holes, Tega-pore™ by 3M, nylon or polyester monofilament weaves, any Delnet® material, rayon, silk, cotton, impregnated gauze and cellulose derivatives. It should be understood that more than one facingsheet32,absorbent30, ortop sheet34 can be employed. For example, multiple facingsheets32 will affect the moisture level at the wound, different absorbents can be combined to increase absorbing effectiveness, and differenttop sheets34 can contribute to stiffness of the composite dressing.

Composite dressing10 can be held over the wound with a variety ofdressing attachments60. FIG. 1 shows two strips of conventional medical tape. Staples, adhesive, Kerlix®, or other suitable type of wraps orattachments60 can be used.

Contact component14 comprises anon-adherent sheet22, and dressingcomponent20 is releasably attached tonon-adherent sheet22 with two parallel strips of doublefaced tape42 running along opposite sides of dressingcomponent20. The term “non-adherent” as used herein refers to materials that are non-adherent relative to absorbent materials like gauze because such structure reduces the adherence of exudate to the non-adherent material.

As further shown in FIG. 1,top side18 extends beyond dressingcomponent20 to provide a mechanism to apply pressure for holdingcontact component14 in place while dressingcomponent20 is pulled.

Non-adherent sheet22 is preferably of a type commercially available from Winfield Laboratories, Inc., P.O. Box 832616, Richardson, Tex. 75083 as N-TERFACE brand interpositional surfacing material. Other suitable non-adherent materials can be employed, for example, any Delnet® materials, Tega-pore™ by 3M, non-adherent foams Adaptic™ non-adhering dressing by Johnson & Johnson, and impregnated gauze.

The application ofcomposite dressing10 involves a single step of applying thecomposite dressing10 overwound12. Since the dressingcomponent20 and thecontact component14 are releasably attached to each other, as opposed to being packaged separately or packaged together but not attached, there is a reduced possibility that a dressing will be applied to a wound without a non-adherent interposed between the wound and the dressing. Since thecomposite dressing10 has thecontact component14 which can be left behind on the wound, the composite dressing functions in a sense as a method of insuring placement of acontact component14 over thewound12. The attachment between thecontact component14 anddressing component20 allows thecomposite dressing10 to be easily soaked and wrung out before application of the composite dressing to the wound.

FIG. 2 illustrates the separation of dressingcomponent20 fromcontact component14.Dressing component20 can be grasped either manually or with an implement and pulled away fromcontact component14. It is preferred that the care provider apply sufficient pressure on the top side of thecontact component14 to hold it in place while the dressingcomponent20 is removed. This insures that thecontact component14 remains immobile on thewound12. In an alternative embodiment, the degree of attachment between the dressingcomponent20 and thecontact component14 can be such that ifcontact component14 adheres to wound12, dressingcomponent20 will separate fromcontact component14 at the interface of the doublefaced tape42 without needing to be held by tape or by a finger. In an alternative embodiment, doublefaced tape42 has a higher degree of adherence to contactcomponent14 than to dressingcomponent20 so that the doublefaced tape42 will remain oncontact component14. Ifwound12 is to be re-dressed, a new composite dressing can be placed overold contact component14, or the new contact component of the new composite dressing can be readily removed so that only a new dressing component is placed overold contact component14. In either case, the intact double faced tape is reused to help retain the new composite dressing or dressing component in place.

After thedressing component20 is removed, the present dressing system provides a “window” through which the wound can be inspected.Contact component14 is sufficiently transparent to allow inspection ofwound12, and sufficiently permeable to allow irrigation, cleansing, washing or treatment ofwound12 throughcontact component14. Various medicines, ointments or other solutions can also be applied via thepermeable contact component14. Irrigation of a wound often entails the forceful spraying or flushing of a solution over the wound. Such methods can remove and otherwise disrupt delicate epithelial cells. With the “window” on thewound12 created by the preferred embodiment of thecontact component14, fragile healing tissue is protected from the forces of irrigation and copious irrigation is unnecessary, since this permeable layer is all that is over the wound. These qualities further justify leavingcontact component14 in place overwound12 for long periods of time while dressingcomponents20 can be repeatedly dressed over the same contact component.

Another advantage attendant with the ability to leave the contact component on the wound is that, if thecontact component14 needs to be removed from the wound, it is less harmful on thewound12, and the patient for the care provider to remove the contact component without the dressing component still attached. In the preferred embodiment, thecontact component14 is constructed such that it can be readily floated off the wound by either quickly soaking thecontact component14 or simply peeling it off thewound12, depending on the healing status of the wound. A conventional dressing requires copious amounts of solution and intensive nursing time to be removed from awound12 by soaking. A soaked, conventional dressing presents a disposal problem in that it is generally saturated and dripping with solution mixed with wound exudate and often tears apart due to the weight of the saturated absorbent. With the preferred embodiment of the invention, the dressingcomponent20 can contain all the needed absorbent and be readily removed from thecontact component14 without needing to be heavily soaked. Thecontact component14 left in place has no absorbent and is easily removed and disposed. Also, the bulkiness of conventional dressings detracts from their ability to be readily peeled off a wound and instead must be blindly pulled away from the wound which increases the risk of injury to the wound.

Another advantage of being able to leave thecontact component14 in place on thewound12 is that when the contact component is transparent, the entire wound can be inspected and observed, which capability enhances the care provider's ability to assess how to further treat the wound or how best to remove the contact component if it needs to be removed. Often there are only one or two points in awound12 that create adherence problems and these points can be readily identified and soaked or treated to facilitate painless removal of thecontact component14.

As previously noted, the dressingcomponent20 is readily removable from thecontact component14 without requiring the use of scissors or dressing shears. Thecomposite dressing10 is configured such that a care provider can readily retain the contact component over the wound and pull the dressing component. In another aspect, the attachment between the contact component and the dressing component is such that the dressing component will readily separate from the contact component when pulled if the contact component adheres to the wound.

FIG. 3 illustrates an alternative embodiment of thecomposite dressing10 according to the principles and concepts of the invention. In this embodiment,top side18 ofcontact component14 does not extend beyond dressingcomponent20, but instead absorbent30 of dressingcomponent20 extends beyondcontact component14 to preventtacky underside39 oftacky film37 from coming in contact withcontact component14. Thus, when dressingcomponent20, comprising absorbent30 stuck totacky film37, is removed,contact component14 is not pulled up inadvertently by its being stuck totacky underside39. If thecontact component14 does not adhere to thewound12, it will come up with the dressingcomponent20 due to being attached at doublefaced tape42. If thecontact component14 adheres to thewound12, dressingcomponent20 will separate at doublefaced tape42 when pulled.Dressing component20 in FIG. 3 can be the product Viasorb® manufactured for Sherwood Medical and disclosed in U.S. Pat. No. 4,561,435 to McKnight et al.

FIG. 4 illustrates an alternative embodiment of the composite dressing of the present invention. In this embodiment,contact component14 comprises a plurality ofnon-adherent sheets22a,22b,22c,each releasably attached together with respective layers of adhesive40band40c.A layer of adhesive40areleasably attaches dressingcomponent20 to the uppernon-adherent sheet22a.These three non-adherent sheets together make upwafer26. The dressingcomponent20 comprises anocclusive material36. Certain wounds and tissue injuries require the use of an occlusive material over thewound12 to shield the wound from outside elements, yet permit a gas exchange. It may be desired to remove theocclusive material36 periodically to treatwound12 with various medicaments or otherwise examinewound12. The present invention allows for the removal of theocclusive material36 without disturbing thewound12 becauseocclusive material36 is separable at layers of adhesive40a,40bor40c.Where separation occurs between layers depends on the degree that the wound exudate has penetratednon-adherent sheets22a,22b,and22c.Depending on where separation occurs, the remainingcontact component14 can be22c;22cand22b;or22c,22band22a.The non-adherent sheets are selected for their affect on wound moisture levels as well has “non-adherent” qualities. This embodiment also illustrates skin attachment means60 on the underside of dressingcomponent20. In this embodiment, dressingattachment60 is an adhesive or tape that allows the sealing of theocclusive material36 onto the healthy area of skin around wound12. Theocclusive material36 can be any of a variety of commonly used materials, for example, Opsite®, polyurethane film, microporous polytetra-fluoroethylene (PTFE) membrane, and hydrocolloid materials.

FIG. 5 illustrates another alternative embodiment of acomposite dressing10 according to the invention. In this embodiment,contact component14 comprises a plurality ofnon-adherent sheets22a, b, cwhich comprisewafer26.Dressing component20 can be releasably attached to the uppermostnon-adherent sheet22a,while the lowermostnon-adherent sheet22cwould be in contact withwound12.Dressing component20 in this embodiment is a hydrocolloid material38. Hydrocolloid materials are commonly employed as a dressing, however, a major drawback of such materials is the propensity to become sticky and bind to a wound. In the embodiment of FIG. 5,wafer26 helps prevent the hydrocolloid material from coming in contact with the wound. Also the additional non-adherent sheets help maintain the proper moisture level at the wound surface. In this embodiment,non-adherent sheet22b,which is sandwiched betweennon-adherent sheets22aand22c,is of a different material thannon-adherent sheets22aand22c.It is presently preferred thatnon-adherent sheets22aand22care N-TERFACE sheets as described in the preferred embodiment, andnon-adherent sheet22bis of a finer mesh or has a finer pore size than22aand22c.A nylon or rayon woven fine mesh or any Delnet® nonwoven material can be used fornon-adherent sheet22b.The non-adherent sheets can be joined with any type ofpermanent bond48 in any suitable manner, for example, by ultrasonically bonding the non-adherent sheets along opposite sides. “Permanent” in this respect means that the bonds are not readily separable when in place on thewound12, but instead require more intensive pulling or manipulation to separate the joined layers and are not intended to function as a release point between the layers. Any suitable hydrocolloid material can be used, for example, DuoDERM® made by Convatec®.Wafer26 can be used as a contact component with materials other than hydrocolloid materials.

FIG. 6 illustrates another embodiment of the composite dressing of the invention. In this embodiment,wafer26 with threenon-adherent sheets22a,22band22ccomprisecomposite dressing10.Dressing component20 comprisesnon-adherent sheets22a,22bjoined together at oppositely situatedpermanent bonds48.Contact component14 comprisesnon-adherent sheet22creleasably attached tonon-adherent sheet22bwithadhesive40.Dressing component20 is useful in treating wounds by affecting the moisture level at the wound. With this embodiment, anadditional dressing28 can be applied overwafer26.Wafer26 defines thecomposite dressing10 in this embodiment. Theadditional dressing28 can be removed with or without dressingcomponent20, depending on the extent of any adherence. It should be understood that varying thicknesses and amounts of non-adherent sheets can be used forcontact component14 anddressing component20.

It should be understood thatcontact component14 can be a variety of materials and combinations. For example,contact component14 can comprise a non-adherent sheet laminated with a hydrophilic material. The hydrophilic material can be used to facilitate the wicking of fluids either away or toward thewound12. In certain wounds it is desired to wick exudate away from the wound to prevent maceration of the wound caused by excessive moisture. In other applications it may be desired to wick medicaments from dressingcomponent20 to the wound to keep the wound moist with such medicaments. Any suitable hydrophilic material can be used, for example, polyurethane foams such as Allevyn™. The product Melolite™ of Smith and Nephew and impregnated gauze can also be used as contact components.

Contact component14 can also be a debridement material. The bottom surface of a bridement material is such that it adheres to a wound, whereby removal ofcontact component14 will debride the wound. In many situations it is desired to remove necrotic tissue from a wound, whereupon one method of debridement is to place a dressing over the wound which will adhere to the necrotic tissue and when removed will pull the necrotic tissue away from the wound. It may be desired to leave the debridement material on the wound for a long period of time to allow proper adherence while, at the same time, wicking of exudate away from the wound or transfer of medicaments or moisture to the wound may be desired. In suchcase dressing component20 can be releasably attached to contactcomponent14 and periodically changed whilecontact component14 of debridement material is left on the wound to completely adhere to the necrotic tissue. Any suitable debridement material can be used, for example, reticulated polyurethane foam or open celled polyurethane foams or gauze.

Dressing component20 can also be a variety of materials and combinations. For example, no top sheet may be desired ifabsorbent30 needs to be continually soaked, or one continuous sheet may make up the top sheet and facing sheet.Dressing component20 can be a transcutaneous electrical nerve stimulator or other devices used to electrically or vibrationally stimulate wound healing.

Absorbent30 used in any embodiment of dressingcomponent20 can be any of a variety of well known absorbent materials, for example, foams, cellulose matrices, hydrocolloid materials, gauze, seaweed products such as calcium alginanate, cotton, and other suitable natural or manmade fibers. In the preferred embodiment, the absorbent material that is used should be lightweight and should absorb large quantities of fluid without requiring multiple dressing layers. The absorbent should be soft and pliable and readily conform to irregular surfaces ensuring intimate proximation of the dressing with the wound surface to prevent pooling of fluids. The absorbent should be flexible and non-binding to allow for a full range of motion. The absorbent can also be sculptured to fit specific areas of a body.

It is preferable that the absorbent is uniformly structured to wick blood and body fluids away from the wound surface and prevent the pooling of fluids next to the wound to prevent maceration of the wound. The absorbent should breathe and not trap excessive heat. The absorbent can be designed to dispense microencapsulated medication or traditional medication to the wound. The absorbent can be moistened with various medications or solutions prior to application or can be impregnated with a desired medicament. Examples of medicaments that may be absorbed into the absorbent are antimicrobial drugs, analgesics, metal oxides and enzymes, etc. The absorbent can be a hydrocolloidal material. The absorbent should readily wick away any fluids before they dry, thereby helping to prevent any bonding or adherence of the contact component to the wound surface.

The state of technology in this field is presently such that new types of absorbents and dressing materials are continuously being developed. Any type of material and combination of materials can be used as a dressing component as long as it is useful for treating a wound and can be releasably attached to a contact component.

FIG. 7 is a top view of an embodiment of the composite dressing.Contact component14 hascontact component perimeter24 anddressing component20 has dressingcomponent perimeter25.Top side18 ofcontact component14 extends beyond dressingcomponent perimeter25. With this configuration, the care provider can easily distinguish dressingcomponent20 fromcontact component14. Moreover, thetop side18 is readily accessible by one or more fingers to apply pressure against the top side of thecontact component14 to prevent accidental pulling of both dressings when attempting to remove theoverlying dressing component20.Contact component14 can be held in place over the wound by applying pressure ontop side18 manually or with a fastener such as staples, tape or wrap. To further facilitate removal of dressingcomponent20, FIG. 7 illustratestab46 andpull tab44 extending respectively fromcontact component14 anddressing component20.Tab46 can be pressed to hold a portion of thecontact component14 in place over the wound.Dressing component20 is formed with apull tab44 having anunderside21. Thepull tab44 is essentially an extension of the material of the dressingcomponent20 that extends beyond the contact component perimeter,24. Such an extension facilitates graspingdressing component20 while holding down thetab46 of thecontact component14. More than onetab46 orpull tab44 can be formed on the respective components. These tabs can even be colored differently to further aid in simplification of the process of selecting and removingdressing component20 relative to contactcomponent14. Also arrows can be printed on top of the dressing component to indicate the most appropriate direction to remove the dressing component and spaces can be left on the composite dressing for care providers to write down information such as the time the particular dressing component was applied. Also, tags can be attached to either thecontact component14, the dressingcomponent20 or both on which various information can be written such as when the particular component was placed on the wound and when it should be removed.

FIG. 8 shows another alternative embodiment of the composite dressing.Contact component14 has acontact component perimeter24 anddressing component20 has a dressingcomponent perimeter25 coinciding with thecontact component perimeter24. A care provider can readily insert a finger between the two perimeters edges to apply a downward pressure againsttop side18 ofcontact component14.Dressing component20 also has anunderside21 which is readily accessible by one or more fingers to facilitate grasping of the dressing component at its perimeter edge. The dressingcomponent20 can be releasably attached to the contact component along a line ofattachment64. In this embodiment, the line ofattachment64 runs close alongside theperimeters24 and25 on three sides leaving a fourth side, or a portion thereof, open to facilitate ready separation. Line ofattachment64 can also be along only two or one sides, or partially on all sides, for example, by leaving one or more corners unattached to allow ready access totop side18 by a finger. The line ofattachment64 can be formed further away from the perimeter edge and be continuous, in which case there would be sufficient room between the line of attachment and the perimeter edge such thattop side18 is accessible by a finger and dressingcomponent perimeter25 is graspable. Line ofattachment64 can be created by imparting various types of bonding energy along the line, for example, ultrasonic, irradiation, heat, laser, mechanical deformation, or a mixture thereof.

FIGS. 9 and 10 illustrate another alternative embodiment of the composite dressing of the present invention. The top view of FIG. 9shows tab46 having a width essentially the same as that of the contact component and extending outwardly beyond the dressing component. Apull tab44 associated with the dressing component is also shown extending outwardly therefrom. In this embodiment, line ofattachment64 is formed continuously around the perimeter of the composite dressing. FIG. 10, which is a cross-sectional view taken alongline10—10 of FIG. 9, shows dressingcomponent20 havingtop sheet34 joined to facingsheet32 aroundabsorbent30 alone line ofattachment64. In this embodiment, line ofattachment64 also serves to attachcontact component14 to dressingcomponent20. A portion of facingsheet32 is extended beyond line ofattachment64 to define thepull tab44.Top sheet34 can also be similarly extended to be part ofpull tab44. A portion ofcontact component14 is extended to createtab46 which can be held down whilepull tab44 is pulled, thereby breaking line ofattachment64. These tabs allow dressingcomponent20 to be readily separated fromcontact component14. Without anytab46 or similar extension ofcontact component14, line ofattachment64 needs to be sufficiently weak to allow dressingcomponent20 to separate fromcontact component14 when pulled, ifcontact component14 should adhere to the wound. Withtab46 or a similar extension, line ofattachment64 can be made stronger becausetab46 allows a care provider to retain thecontact component14 in place when dressingcomponent20 is pulled and removed. Line ofattachment64 in this embodiment is preferably formed ultrasonically, but can also be formed by irradiation, laser, mechanical deformation, etc.

With the foregoing principles and concepts of the invention in mind, it is contemplated that the dressing disclosed in U.S. Pat. No. 4,667,665 to Blanco et al. can be modified to arrive at the embodiment shown in FIGS. 9 and 10. This can be carried out by adding tabs to the appropriate parts of the dressing such that one tab can be pulled to readily remove the upper portion of the dressing with the absorbent, while pressure is maintained on the other tab to hold the lower sheet in place. While it is preferred to form a tab for each component, the adding of a tab only to the lower sheet can be carried out since the top of the dressing can be pinched and pulled like the embodiment pictured in FIG.2. The strength of the ultrasonic bond around the perimeter should be such to compromise the integrity of the dressing so as to allow ready separation of the upper portion from the lower sheet.

Even ifcontact component14 does not adhere to wound12 it may still be desired to only remove dressingcomponent20 and leavecontact component14 in place on the wound. For example, if thewound12 is to be swabbed with some type of medicament it may be desired to leavecontact component14 in place over the wound to facilitate the spreading of the medicament over the entire surface of the wound while protecting the wound from any discomfort. Also even ifcontact component14 is not adhering to a wound, it can help maintain the integrity of newly formed granulation tissue and/or epithelial cells which were beginning to form in the wound. The contact component can also protect the healing cells and tissues from irrigation and cleansing forces.

FIGS. 11-13 illustrate another embodiment of the composite dressing of the present invention. In this embodiment, an adhesive material such as doublefaced tape42 has an adhesive top58 that releasably attaches dressingcomponent20 to contactcomponent14 and has an adhesive bottom57 which faces the top side of the contact component and extends beyondcontact component perimeter24 to holdcontact component14 in place overwound12. FIG. 11 illustrates the composite dressing as packaged. Backing strips43 are used to cover the exposed portion of doublefaced tape42. When the composite dressing is ready to be applied to the wound, backing strips43 are removed and, as FIG. 12 shows, the composite dressing is placed over the wound so that the exposed portions of doublefaced tape42 adhere to healthy skin around the wound. When the dressing component is removed, as shown in FIG. 13, doublefaced tape42 holdscontact component14 in place over the wound.

FIG. 14 shows a perspective view of an alternative embodiment having anadhesive material56 with an adhesive bottom57 and anadhesive top58. Adhesive top58 is optional because dressingcomponent20 can be attached to contactcomponent14 by other means.Adhesive material56 has a central square cut-out to facilitate the interaction of the dressing component with the wound. Perforations or a sufficiently permeableadhesive material56 can also be used in lieu of the cut-out. Adhesive bottom57 extends beyondcontact component perimeter24.

FIGS. 15 and 16 illustrate an alternative embodiment of the present invention. FIG. 15 illustrates an alternative technique to releasably attach dressingcomponent20 to contactcomponent14 by folding contact componentmarginal edge53 around dressingcomponent perimeter25 to formfold54. In this manner, dressingcomponent20 remains in the folded edge of thecontact component14, yet can become unfolded when pulling on dressingcomponent20 and ifcontact component14 remains adhered to the wound or is held in place over the wound. FIG. 16 illustrates dressingcomponent20 being separated fromcontact component14. Additionally, an adhesive or a double faced tape can be added intofold54. It should be understood that any style or arrangement of folding can be used if it allows the dressing component to separate from the contact component. Dressing componentmarginal edge55 and contact componentmarginal edge53 can be folded together upward or downward or one of the marginal edges can be folded around the other component's perimeter.

Any method of mechanically deformingmarginal edges53 and55 together can be used, for example, crimping, puncturing the marginal edges together with a series of punch holes, or heating plus some type of deforming method.

It should be understood that the dressing component and contact component can be attached to each other at any vicinity between the two components. For example, adhesive or other attachment methods can be randomly distributed across the top side of the composite dressing or lined along opposite sides of its perimeter. In the preferred embodiment, two-sided tape can be run either continuously or intermittently along parallel opposite sides. FIG. 7 illustrates the two parallel strips oftape42. Any folds or crimps can be formed continuously or intermittently around the perimeter of the composite dressing or only along opposite sides. Also, one or more corners of the composite dressing could be left without any attachment so as to provide a starting point for ready separation of the components. Other means for releasable attachment of the dressing component to the contact component include ultrasonically tacking the dressing component to the contact component, creating an electrostatic attraction between the dressing component and the contact component, heating the contact component and dressing component together, using irradiation or laser techniques, and/or applying pressure to the dressing component and contact component.

The attachment of the dressing component to the contact component allows for the composite dressing to be packaged as a single dressing or product in a single package and sterilized as a single dressing in a single package. When the composite dressing is ready to be used the single sterile package can be opened and the composite dressing is removed with the dressing component and contact component attached to each other so that placement of the composite dressing over the wound is performed in one easy step. When re-dressing a wound that has a contact component remaining thereon, a composite dressing can be removed from its package and the new contact component quickly separated from the dressing component to allow placement of the new dressing component over the old contact component. However, it may be desirable to place the entire composite dressing over the existing contact component in order to help maintain the desired level of moisture at the wound site or as a further precaution against incorporation of material from the dressing component into the wound.

FIG. 17 illustrates an alternative embodiment of the composite dressing in a rolled form.Dressing component20 andcontact component14 are releasably attached and rolled together.

Another aspect of the present invention comprises a method of treating a wound with a composite dressing. The method comprises the first step of placing a first composite dressing on the wound. The first composite dressing comprises a first contact component for contacting the wound and a first dressing component releasably attached to the first contact component. The second step comprises pulling the dressing component from the wound, whereby if the contact component adheres to the wound and/or is held in place over the wound, the dressing component will separate from the contact component. Alternative and additional steps can be performed, for example, placing a second composite dressing over the wound after the first dressing component has been separated, or in the alternative, the second composite dressing can be split into its two components and the second dressing component can be applied over the first contact component still over the wound. Also, the first contact component can be removed after the first dressing component is removed. Without the first dressing component attached to the first contact component, removal of the first contact component is easier and can be facilitated by rinsing.

FIG. 18 illustrates the preferred embodiment of an interpositional wafer, in accordance with another aspect of the present invention.Wafer26 in this embodiment can be used alone over a wound to protect the wound, control the moisture level at the wound, and/or facilitate application of various medicaments to the wound. According to this aspect, the wafer is interposed between a wound and a hydrocolloid dressing to prevent the hydrocolloid material from bonding to the wound and to allow a traumatic removal of the hydrocolloid dressing from the wound. The wafer also helps maintain a proper moisture level at the wound underneath the hydrocolloid. The preferred embodiment is the same wafer described in the embodiment of FIG.5.Wafer26 comprises threenon-adherent sheets22a,22b,and22c.It has been found that when the middlenon-adherent sheet22bhas a tighter mesh than22aand22c,hydrocolloid material is able to interact withwound12 but does not stick to wound12. At the same time the proper level of moisture is maintained at the wound. In the preferred embodiment, outer non-adherent sheets are Delnet® CS-8 distributed by Applied Extrusion Technologies, Inc.Middle sheet22bis preferably Delnet® CSD0707-25. Any combination of Delnet® materials can be used. Other types of non-adherent materials that can be used inwafer26 are any non-woven polymer, monofilament weaves, nylon, polyester, rayon, cellulose, Tega-pore™ by 3M, non-adherent foams such as hydrophilic polyurethane foam dressings, Adaptic™ non-adhering dressing by Johnson & Johnson, etc. The non-adherent sheets can be coated with substances to enhance their non-adherent characteristics. The two other sheets do not need to be the same material.

Wafer26 can be used under any dressing as well as used alone.Wafer26 can be secured over the wound in any conventional manner. Preferably, the non-adherent sheets are joined bypermanent bonds48 along opposite edges. Any type of process of joining the sheets can be used, for example, ultrasonic, pressure, laser, adhesive, etc. “Permanent” as used herein means that the bonds are not readily separable when the wafer is in place on a wound, but instead require more intensive pulling or manipulation to separate the joined layers.

In practice,wafer26 is packaged alone or in a pack of several wafers. A wafer is removed from the package and secured over a wound. Then a suitable dressing can be placed over the wafer. When a hydrocolloid dressing is placed over the wafer, removal of the hydrocolloid often pulls up the wafer, but, due to the non-adherent properties of the wafer as well as sufficient moisture at the wound as a result of the wafer, a traumatic removal of the hydrocolloid can be achieved.

Although the present invention has been described with respect to a preferred embodiment and alternative embodiments, various changes, substitutions and modifications of these may be suggested to one skilled in the art, and it is intended that the present invention encompass such changes, substitutions and modifications as fall within the scope of the appended claims.

Claims (21)

What is claimed is:

1. A composite dressing for a wound, comprising:

(a) a contact component constructed of a continuous sheet that covers all portions of the wound over which the contact component is applied, an entire extent of a bottom surface of said contact component being substantially free from adhesives and thus non-adherent to the wound, said contact component also having a top side, and said contact component is liquid permeable and allows permeation of liquids therethrough with respect to the wound; and

(b) a dressing component adapted for use in treating the wound, said dressing component and said contact component being releasably attached directly to each other such that they can be applied to the wound together as a composite dressing in one step.

2. The composite dressing of claim1, wherein said contact component comprises a single non-adherent sheet.

3. The composite dressing of claim1, wherein said contact component comprises non-adherent sheets superimposed over each other.

4. The composite dressing of claim1, wherein said contact component comprises a plurality of sheets, ones of said contact component sheets having a mesh that is finer than that of the other sheets of said plurality.

5. The composite dressing of claim4, further including three said sheets bonded together, with a middle said sheet having a finer mesh than the other two sheets.

6. The composite dressing of claim4, wherein a mesh tightness of at least one said sheet is selected to control a moisture level of the wound.

7. The composite dressing of claim4, wherein a first and second outer sheet comprise the same material.

8. The composite dressing of claim1, wherein said contact component sheets are constructed of a material selected from the group consisting of non-woven polymers, monofilament weaves, nylon, polyester, rayon, cellulose, polyurethane foams, or any mixture thereof.

9. The composite dressing of claim4, wherein said plurality of sheets having coinciding perimeters.

10. The composite dressing of claim4, wherein said plurality of sheets are joined along at least two opposite edges.

11. The composite dressing of claim4, wherein said dressing component is constructed of a hydrocolloid material, and said contact component sheets have meshes formed so as to prevent said hydrocolloid material from adhering to the wound.

12. The composite dressing of claim1, wherein said contact component is coated with a substance which increases a non-adherent nature thereof.

13. The composite dressing of claim1, further including a hydrocolloid material to maintain a desired moisture level to the wound.

14. The composite dressing of claim13, wherein said dressing component comprises said hydrocolloid material.

15. The composite dressing of claim13, wherein said hydrocolloid material is disposed between said dressing component and said contact component.

16. The composite dressing of claim1, wherein said contact component has a contact component perimeter and said composite dressing further comprises an adhesive material interposed between said contact component and said dressing component, said adhesive material having an adhesive bottom facing said top side of said contact component and extending beyond at least a portion of said contact component perimeter.

17. The composite dressing of claim16, wherein said adhesive material has an adhesive top facing said dressing component.

18. The composite dressing of claim1, wherein said dressing component has a dressing component perimeter, and a top side of said contact component extends beyond said dressing component perimeter.

19. The composite dressing of claim1, wherein said bottom side of said contact component comprises a debridement material that adheres to the wound such that removal of said contact component debrides the wound.

20. The composite dressing of claim1, wherein said contact component is laminated to a hydrophilic material.

21. The composite dressing of claim1, wherein said dressing component comprises an absorbent material adapted for absorbing exudate that passes through said contact component.

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